We mostly focus on freshwater here, but I want to take a minute or two to introduce a peaceful giant of the sea: The Ocean Sunfish (Mola mola). 

molamola by per ola norman
Above: An Ocean Sunfish (Mola mola) - By Per-Ola Norman (Own work) [Public domain], via Wikimedia Commons


The Mola mola is found in the order Tetraodontiformes – a fancy term for the group that contains fish such as the pufferfish, triggerfish, boxfish (and, of course, the ocean sunfishes). The cool thing about this order is that they split from other fish around 80-195 million years ago1, which means they have no close relatives and have evolved many special adaptations that make them the strange looking creatures they are today.

Many fish have special adaptations, and a lot of these are not all visibly obvious. Although, his isn’t the case for the Mola mola, as you may notice when looking at them. Compared to our small aquarium fishes, the M. mola can reach a whopping 2.3 tonnes, with a length of 2.7 metres2 - that’s the size of a (very small) elephant! However, less elegant than an elephant, the Ocean Sunfish lacks a caudal (tail) fin, replaced by a ‘pseudotail’ called a clavus. The dorsal (top) fin is so large that people may mistake fish swimming at the surface for sharks, and is used alongside the anal (bottom) fin for most of its motion - giving it a speed of 3.2km/h3. Much like pufferfish, its teeth are also fused to form what’s often called a beak - which they cannot actually close!


1024px mola mola skelett naturhistorisches museum wien
Above: A skeleton of the Mola mola at the Natural History Museum, Vienna - By Sandstein (Own work) [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons


Starting out at a tiny 0.25cm larva, this fish can grow up to 60 million times in size3, gaining up to 0.82kg per day4. What do they have to eat to gain this kind of weight? Mostly jellyfish and zooplankton (with the occasional sponge, squid, eel larvae and small fish thrown in). The female Ocean Sunfish can also lay 300 million eggs in one go - with this, it’s seems pretty safe to assume that these guys have their fair share of predators,  seeing as we aren't overrun by these plate-shaped giants! Predators of the Mola mola include sea lions, orcas, large sharks, and of course - humans.

Despite their size, the Mola mola is considered a peaceful fish (provided you aren’t a jellyfish, of course). Whilst I’m not a huge fan of approaching aquatic life so closely, this video shows the gentle giant swimming alongside a group of divers. For those who aren’t keen on searching the depths of the oceans for the chance to see one of these guys, I end this article with a rather upbeat video of a small Mola mola feeding from the Monterey Bay Aquarium in California, a favourite Youtube channel of mine. I hope to see an Ocean Sunfish for myself one day, but for now, videos will have to do!




This always sounds pretty dodgy without context, but a common question is "Can I mix Africans and Americans?" - referring to the fish in the family Cichlidae, of course. For most cases I personally would not recommend it; however, what seems like a simple yes or no question actually has several different issues to consider, and there are many different opinions as to whether mixing Cichlids is a good idea or not. So, instead of us choosing for you, this article hopes to outline some of the things to think about when looking at keeping African and American Cichlids together.


What are African and American Cichlids?

As outlined here, Cichlids come from all over the African and American continents. The Cichlids we keep are usually sorted into three different categories: New World Cichlids (or American Cichlids, which may be split into South American Cichlids and Central American Cichlids), African Cichlids and Dwarf Cichlids (which may come from the Americas or Africa).

For this, we're focusing on the aggressive African Cichlids that come from three of the great lakes: Lake Malawi, Lake Tanganyika and Lake Victoria, along with the larger American Cichlids that come from both South and Central America. Dwarf Cichlids tend to not be good mixes with most other Cichlid species in general, as they are often more sensitive to stressors. 

around the world of cichlids poster


Why Can't I Just Combine Them?

You may have heard of some combinations of the following species - Electric Yellow Cichlids, Demasoni Cichlids, Convict Cichlids, Angelfish, Discus, Jaguars, Oscars, Frontosa and many of the other colourful medium-large "feature" fish available in NZ, however where they come from and how they live can be pretty important as to whether they will really thrive together in a tank. As fishkeepers, we get our passion and joy for the hobby from watching our fish show bright colours, swim around actively, breeding and living long, healthy lives - essentially, thriving. We want our fish to thrive because it's best for our fish, our tank's ecosystem and us!

It can be tempting to mix fish that aren't always recommended to go together, and it may give you months of enjoyment watching these fish survive in the same tank. The issue is, unfortunately, the recommendations against mixing fish are often based on many years of many different experiences from fishkeepers around the world. For some fish, sudden changes like aggression (for example, when spawning is triggered) may lead to, ahem, one fish being the only one left in the tank. For other fish, it can be the long-term effects that aren't necessarily visible straight away.


Water, Water, Water

One of the primary differences between New World Cichlids (particularly those from South America) and African Cichlids are the conditions in which they thrive in the wild. New World Cichlids often come from blackwater rivers which are named due to the heavy staining from tannins. Tannins are produced as water runs over decomposing material (such as leaves and wood) and soil, and although they just produce a yellow colour in our tank water, in the wild these tannins are in such a high concentration that along with solids in the water they produce waters so dark they can be impossible to see through. Along with discolouring the water, tannins also increase acidity of the water - causing the pH to go as low as 5.0 and little to no hardness.


In contrast, African Cichlids from lakes come from clearer, bluer waters that are very hard and basic (alkaline). In fact, their pH can even get up to 9.0![1] Although 5.0 and 9.0 are only four numbers apart, there's actually a pretty major difference. The pH scale is logarithmic, meaning an increase in 1 on the scale means the water is actually 10 times more alkaline. This means that a pH of 5 is 10,000 times more acidic than a pH of 9.0 (and a pH of 9.0 is 10,000 times more alkaline than a pH of 5.0). 


 negro river lake malawi comparison

Above: Rio Negro in South America By Simara Couto de Abrantes (Own work) [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons Left, Cape Maclear in Malawi, Africa Joachim Huber [CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons Right.


Now, I hear you say "But our fish aren't wild fish?" and you're completely right. Some fish in our care may be considered hardier than their wild counterparts, however there are two major situations that can't be predicted without knowing the lineages of our fish (which unfortunately in New Zealand, we rarely have access to). 


The first is how many generations ago our fish lived in the wild. For some fish, such as certain (typically more pricey) African Cichlids, we still have wild fish in the trade (although these are usually labelled as such). This means that it's nearly impossible to tell whether your fish had ancestors in the wild one generation ago, or 100 generations ago. In this case, it's usually safer to lean towards the former - it's better to put a fish in its known ideal conditions, rather than the unknown conditions that it may have grown up in.


The second is that intense captive breeding of fish may even reduce how hardy they are. Some people feel that they have more luck keeping wild-caught fish as they believe fish that have undergone years of captive breeding become less adaptable to fluctuation. Fish in the wild that have wet and dry seasons (such as New World Cichlids) experience fluctuations in temperature, pH, hardness and so-forth as the seasons change, whilst fish in captivity tend to have fairly stable parameters. This means some people feel that generations of a fish raised in a pH of 6.0 is going to be less likely to thrive in fluctuating or differing parameters than wild-caught fish!


A Herbivorous Fish Walks Into a Bar...

Another issue to note is the specialization of diets between different fish. Many African Cichlids, particularly those from Lake Malawi, have specialized mouths and teeth for rasping algae from rocks (Although a cool example of adaptation, I personally think they look a bit silly!). Compared to this, most American Cichlids are predatory and tend towards more carnivorous-based diets.


 full on fuelleborni

Above: Labeotropheus fuelleborni By Lee Nachtigal (Flickr: Full on Fuelleborni) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons


Of course, the different species of fish in community tanks often have different dietary requirements. However, many cichlids (including those that graze on algae) readily eat from the surface of the tank - making it difficult to accommodate the different diets of each fish species. One major concern that arises from this is Malawi Bloat.

Malawi Bloat is a bit difficult to define as it is often used for a range of diseases that cause the similar ‘bloating’ symptom, however in this case we’re referring to bloat that’s caused by diet.

Herbivorous fish have a long digestive tract and tend to digest food for a longer amount of time than carnivorous fish (which have short digestive tracts)[2]. While plant matter is suitable for sitting in the digestive tract of a herbivorous fish, meaty foods tend to cause irritation, leading gas buildup and swelling (note: whether this swelling is caused by a parasite or bacterial species in Malawi Bloat is debated). Along with creating swelling in the fish (which generally isn’t nice), this can put pressure against other organs, particularly the swim bladder. One main symptom of swim bladder issues is a lack (or increased) buoyancy of the fish - which can be a pretty scary symptom to deal with!


For both long-term and short-term benefits for the fish, an adequate diet is key - especially as internal issues caused by diet can be tricky to notice, diagnose and treat (often requiring antibiotics).


Cichlids Get Grouchy

One of the main features that make Cichlidae such an appealing fish to keep is their strong personalities. Unfortunately, with these strong personalities, Cichlids can be tricky to house together. Generally, the levels of aggression in Cichlids can range quite significantly among species, however almost all Cichlids are known for becoming territorial when breeding. This can become a problem when it comes to the size and 'hardiness' of the fish being beaten up.


Some fish are much better at handling stressors in their environment, while others might not fare so well. For example, the aggressive Mbuna may be able to readily handle their boisterous tankmates, but the Angelfish from South America might not be so forgiving - leading to an increased risk of illness in any wounds that might occur from being housed with aggressive Africans.


Size is also a big factor. Dwarf Cichlids for example, don't have any real kind of dwarfism involved - they're just much smaller than a 40cm Oscar cichlid! This means that the basic rule of "a fish will eat whatever it can fit in its mouth" applies, along with taking into account the increased aggression of Cichlids in general. However, it is worth noting that even in specific locations in the wild, there can still be a wide range of sizes and temperaments in the fish species present. A general rule of thumb that might be useful is to consider the diet of the fish - a smaller fish that eats predominantly insects in the wild might not get along so well with a larger fish that predominantly eats other fish in the wild.


apistogramma macmasteri male

Above: An Apistogramma macmasteri male. This species may have attitude, but is considered a Dwarf Cichlid - or an easy meal, if you're a Mbuna Cichlid! 


So... What's The Answer?

That, my dear reader, is entirely up to you. I know - it's a lot of information to take in. It's pretty scary figuring out which fish are going to be best buddies, versus which ones would be best separate (they don't do a very good job of telling us)! Personally, I prefer to put fish together that come from similar environments and fit their own niche in the tank (Biotopes being my favourite). However, that might be considered a bit more specific than some prefer, and that's a-okay.


What I hope to have provided in the above article is the opportunity to learn the difference between fish that live in quite varying environments and to have now provided the knowledge to consider for yourself what's best for your fish. An educated fishkeeper keeps happy and healthy tanks, which helps to keep a happy (and healthy?) fishkeeper!


Do you have any questions, or just want to say Hi? Feel free to Contact Us or visit our Facebook Page!




One classic fish known for treating reproduction and gender a little bit strangely is the Clownfish, in which male Clownfish change sex when a female passes away – but have you ever wondered if there are any Freshwater fish that don’t go by the norm when it comes to reproduction? Although these species aren’t available in New Zealand, they are one of the few known fish to participate in asexual reproduction and self-fertilization!


The Amazon Molly


poecilia formosa amazon molly

Above: The Amazon Molly (Poecilia formosa). Photo by Robbie N. Cada of Fishbase


The Amazon Molly (Poecilia formosa) is a unisex species – all (or, in most cases, almost all) fish of this species are females. While this fish is a species of its own, the Amazon Molly is actually a hybrid of two other Poecilia species (although reports differ as to which fish are the parent species).

They reproduce in a similar way to what’s called Parthenogenesis, which is known in species such as the New Mexico Whiptail lizard (Cnemidophorus neomexicanus), which is a method of asexual reproduction that produces (typically female) cloned offspring.

Their method, however, is Gynogensis, which is even stranger. Gynogenesis means they require a ‘trigger’ from a male of a different species in the Poecilia genus. The female ‘discards’ the DNA from the male after mating, and this begins the development of eggs into embryos. Although, in rare cases, they may keep the DNA from the male parent and develop what is called a Triploid male offspring – triploid meaning they have kept the two chromosomes from the female (in humans, this would be XX) and the chromosome from the male (in humans, this would be Y). While this does occur, it’s not necessary for their species’ survival and these triploid fish usually only exist in small numbers.

Because a male is required to reproduce (kinda!), this species have to co-exist with other Poecilia fish – two species they are known to mate with are the well-loved Sailfin Molly (P latipinna) and sometimes the common Molly (P sphenops), however there’s a wide range of species they will mate with in the same genus.


The Amazon Molly truly is a strange fish, particularly due to the unlikelihood of an asexual fish species surviving for so long!


Mangrove Rivulus


kryptolebias marmoratus aquarium tropical du palais de la porte dorée 10 04 2016 2

Above: Mangrove Rivulus (Kryptolebias marmoratus). Photo by Vassil, Wikimedia


Even stranger is the Mangrove Rivulus (Kryptolebias marmoratus), a species of Killifish which is especially known for being able to survive out of water for 66 days! Although this is fascinating, it’s not quite what we’re interested in today.

The Mangrove Rivulus is known as one of the only self-fertilizing hermaphroditic vertebrate. That’s a lot of long words in a row – basically, the vast majority of the species has both female and male organs, and these can be used to produce clones from a single fish. This method of self-fertilization allows for ‘self-repair’ during the phase of meiosis (the production of sex cells), which prevents a lot of the issues caused by asexual reproduction, and this species lacks problems caused by heavy inbreeding.

Although the Mangrove Rivulus is almost always hermaphroditic, under ‘stressful’ situations, males can be produced. Oddly enough, when this occurs, hermaphroditic fish may act as females and reproduce sexually with the male population. Much like the Amazon Molly, these strange forms of reproduction make it a fascinating subject for scientists studying subjects such as Evolution.



Whilst these fish aren’t commonly kept in the hobby and may not be available in NZ, it’s always interesting to find out the unusual adaptations of fish that are so closely related to our beloved pets. Although I’m personally quite relieved our Killifish don’t try to spend so long out of the water!


dsc 0665

Above: A readily available species, the Steel Blue Killifish Female (Fundulopanchax gardneri)


Have any questions? Feel free to let us know in the comments below, or send a question through our Contact Us!





Puffers, specifically Dwarf Puffers, can be tricky little fish. While recommended for smaller tanks, many people take these guys on without properly knowing how to look after them. Dwarf Puffers are true freshwater puffers, and require a good diet, lots of space space and good water conditions, they simply won't tolerate any less! However, they are extremely rewarding fish that I would recommend every fish owner keeps at least once in their life. Puffers are a personal favourite of mine, my current dwarf puffer being a female kept by herself in a 31L/8gal tall tank - she's full of personality, but she's also been on death's edge a couple of times.


160605 dpf

Above: Look at all that space!



The diet of a puffer, regardless of species, should consist predominantly of molluscs and/or crustacea, but treats such as bloodworms, white worms and other live foods can be offered too. Puffers will often eat until full, so it's really easy to tell how much to feed them - regularly top up the tank with snails and then feed them the live foods until they swim away! My puffer will eat about 4-5 white worms until she's full, and I'll feed these white worms around every second day, supplementing the rest of her diet with snails.

These guys consume a lot of snails though, so you should be prepared to grow them out in another tank regularly. I've found Ramshorn and Pond snails best, as my puffer tends to reject Malaysian Trumpet snails as they have rock-hard shells and they bury themselves in the gravel during the day (and puffers rely on their eyesight to feed!). White worms and bloodworms aren't particularly nutritious, which is why they're often fed purely as treats. However, I've used them regularly in the past to fatten up sickly puffers who may have trouble eating and getting to the snails.

In the top of the tank is a bloodworm feeder - this is particularly useful to keep worms in place. Puffers are messy feeders and will leave all sorts of food lying around, along with snail shells scattered everywhere. They're also strong hunters, so will have fun picking worms out of the feeder!

The best way to tell how well fed a puffer is is to look at its body shape. A good puffer will be round and fat, while a malnourished puffer will be skinny and bony. "Convex, not concave" is the best way to tell how healthy a puffer is. If you're finding your puffer concaved, then it is most likely sick.

Dwarf Puffer with Internal Parasites

Above: A severely malnourished puffer


In relation to the above, it's very important to pay attention to the health of a puffer when buying it from the store. Buy puffers from good, healthy stock where the majority are "convex" and active. It's often useful to ask the shop assistant to feed the puffers in front of you to see whether they're healthy and eating. Puffers are very friendly and curious fish, and should be coming up to the tank to say "hi". If they appear lethargic, or are shying away from humans, it could very easily be sick. In my experience, puffers often come into stores with parasites which can be hard to cure and will often lead to the death of the fish. The puffer above is the same in the first photo, and recovered after some good food and several doses of Praziquantel.



Housing and tankmates

As mentioned above, puffers pretty messy eaters. Because of this, they require a filter and regular water changes. I do a 50% water change once a week on the tank above, as puffers are very sensitive to deteriorating water conditions. Never add puffers to biologically "immature" tanks. Tanks that are cycling are not suitable for them and will almost certainly kill your fish. It's also best to have stable, aged water - I personally kept tetras in the already-cycled tank for around 3 weeks before removing them and adding the puffer. With these guys, a Nitrate test kit is a must! They can quickly fall ill if a tank is left too long without a water change. Plants are always extremely useful to help with this, as they help to remove nitrates along with the water changes. As with all fish, a dechlorinator is required.

Along with removing Nitrates, plants are also an important part of their environment. Puffers are intelligent fish, and easily bored. They require plenty of hiding places - not only to create territory, but to keep them interested! A bored puffer will often scale the tank walls, looking for something to do. Caves, plants and other hiding spaces will provide them with safety and cover, along with interesting places to explore and hunt in.

I recommend a minimum of 5 gallons/21L for one puffer, and footprint is always more important than height! A larger footprint allows you to create more territory space, and more places to explore. A 10 gallon/38L long will be suitable for 3 puffers, but only for those who are experienced and are able to give them plenty of spaces and able to make sure all puffers are getting along well. A 18gal/70L could probably hold around 3-8 puffers depending on your level of experience and the personalities of the puffers.

Places to hide are also extremely important when keeping multiple puffers or puffers with other species. I personally do not recommend keeping puffers with other species. I also recommend caution with keeping multiple puffers. If keeping multiple, it is recommended to keep one male to multiple females. It is also necessary to keep them in groups of 3+ (unless spawning) to help "spread" aggression. Some people keep them in groups bigger than 10, and have even reported spawning in such large groups! But be cautious as some puffers are more aggressive than others, so be prepared to remove aggressors to keep them on their own. Puffers also often aren't old enough to sex in store, so you will likely not be able to maintain the ideal sex ratio. They will also quickly turn on a sickly tankmate, nipping at it until it dies. So always keep a close eye on any fish showing illness so that you can remove them before it gets attacked.

Sexing a puffer can be difficult when young, but when old enough the males will develop a stripe on their bellies and will often get "wrinkles" around their eyes! Females tend to be rounder, less colourful, have small spots and lack the above features.

The reason why I personally don't recommend tankmates is because of the common misconceptions around the tankmates often recommended by others. Even the fastest of fish can become prey for puffers, which are known to shred fish much bigger than themselves. Puffers may be "peaceful" when young but will often become very aggressive when older. Keeping them with any longfinned or slow moving fish is a definite no-go!

Otocinclus ("Otos") are often recommended because of their small size. Otos are indeed very small fish, but are in fact shoaling fish! This means they will thrive in groups of 5 or more - so while they may be small, they will need a slightly larger tank than the minimum puffer tank size as they will have a larger bioload and will need more space. Otos are also recommended as people find their puffers do not pick on them, however they are really kept with varying success and people often find the Otos disappear one day! Just like the puffer, Otos are even more sensitive to water conditions and are known to die during the acclimation process! I've found Otocinclus very rewarding, but very sensitive and I personally have not attempted to keep them with my puffer.

Bumblebee Gobies (BB Gobies or Brachygobius spp.) are also often seen in the tanks with puffers at the pet store. There are two species of BB Gobies - one requires brackish water and the other will thrive in brackish water, but will survive in freshwater. However, you'll possibly find that it is stressed when kept in freshwater, often cutting time from its lifespan. As mentioned above, puffers can be peaceful when young, but can be aggressive when older, so you may also find your BB gobies disappearing one day! I simply do not recommend these because of their incompatible water conditions - Dwarf Puffers cannot be kept in brackish water, and Bumblebee Gobies are prone to stress in fresh water.

Otocinclus shoaling / schooling

Above: Three Otocinclus hanging out together


Keeping puffers has been extremely rewarding for me, and my female is probably my favourite fish! She recognizes me, and knows when she's about to get fed! She will also easily feed out of my hand, and will swim around my fingers in curiosity. Puffer fish quickly became one of my families of fish and I eventually intend on owning all sorts of different types of puffers! But for now, the dwarf puffer is my favourite and the first puffer I recommend to anyone. Compared to others, they're easy to look after and are reasonably unfussy when it comes to foods. These guys are absolutely wonderful if you have space requirements and I would recommend them to all!


Healthy dwarf puffer female


My puffer says thank you for reading, and that she really hopes you'll give them a go! I can't think of a fish more interactive and curious than these little guys! If you want to know more about puffers, feel free to contact us, or ask your local fishkeeping forum such as the FNZAS!


Anabantoidei is a sub-order of fish that posses labyrinth organs, which are specific organs designed so that the fish may breathe air. Many Anabantoids are referred to as Gourami which also includes your common Siamese Fighting Fish (Betta Splenden). Here we will discuss your common gourami from the family Osphronemidae and how to look after them. Gourami quickly became one of my favourite fish, as they all show such different personalities and can easily learn their owner's routine. Bettas are commonly regarded as some a fish with one of the best personalities out there, and you can even teach them tricks!


Common Gourami species can include:

  • Three Spot Gourami, Trichopodus trichopterus
  • Pearl Gourami, Trichopodus leerii
  • Dwarf Gourami, Trichogaster lalius
  • Honey Gourami, Trichogaster chuna
  • Thicklipped Gourami, Trichogaster labiosa
  • Indian Banded Gourami, Trichogaster fasciata
  • Siamese Fighting Fish, Betta splendens
  • Sparkling Gourami, Trichopsis pumila (Less common here in NZ, and not for the beginner)


Female Thicklip Gourami

Above: Thicklip Gourami female, Trichogaster labiosa


There are other, more sensitive gourami available such as the Chocolate gourami, Paradise gourami and Giant gourami, however these can differ greatly in care (for example, the Chocolate gourami is a mouthbrooder and even prefers shoals!) and are certainly specialist fish.



What do I want my tank to look like?

Gourami are from Asia and tend to come from warm climates where the water is shallow and has little to no flow, and there is little dissolved oxygen available (hence the need for breathing air). Their habitats are usually full of plants, and is stained yellow by the tanins from leaf litter. Some of these areas go through extreme wet and dry seasons, and their habitat can go from having vast amounts of water to small puddles! Usually they will have spawned in time for the dry season, but Gourami species are not annuals and can live anywhere from 3 to 10 years!



Water Conditions

The pH for gourami tends to be pretty low, anywhere from 5.0 to 7.0. To achieve this, you can use Peat moss (in the substrate or filter), Leaf litter and Driftwood which all leak out tanins, a substance which lowers the pH over time. Tanins, however, will turn your water a yellow tea-stained colour! Many people don't like this effect, but it really does recreate the natural habitat of these fish and, in my opinion, looks great against a black background. While ideal pH is desired, it's more important to make sure your pH is consistent! Very "soft" water (low KH, also known as carbonate hardness) is prone to pH swings and if you're unfamiliar with pH and KH it's best to try to keep your pH consistent, rather than aiming for a lower acidity. Remember, whenever you change your water from the tap you are putting water that may range from 6.5 to 8.8 and can cause a swing which can shock your fish.

Some species of gourami, such as Dwarf gourami and Honey gourami, are pretty well known for developing diseases such as fungus, which can be difficult from having territorial fish! Disease develops mostly through stress and poor water quality, but is also from poor quality of the fish itself (as many of these fish are inbred to keep such lovely colours). It's important to add gourami a while after (about 1-2 months) the tank's cycle is established - this way, your new gourami are less likely to be stressed out and get sick.




Their diet tends to consist of insects and vegetable matter, and most gourami are omnivorous, however the amount of meat:vegetable matter a gourami eats depends on their species. For example, I have found the Honey gourami to eat a lot of vegetable matter, whereas Siamese Fighters are known to be predominantly carnivorous. Some gourami even spit at the surface like Archerfish in order to catch insects! While they appear to lose it over time, it can be very fun to watch once you get them home and little drops of water fly everywhere! Gourami get very excited over food anyway, and can make quite the splash as they all rush to get some!


Thicklip Gourami Feeding

Above: Two Thicklip gourami share a shrimp pellet


Sexing Gourami

Most Gourami are sexed in the same way. Below is a picture of possible identifiers, although many species have specific traits.


Sexing Gourami infographic


The ways of sexing gourami definitely vary between species. Five signs that seem almost universal are:

  • Male gourami becomes territorial as it matures
  • Male gourami builds bubble-nests (with the exception of mouthbrooders)
  • Male gourami has a pointed dorsal, female with a rounded dorsal
  • Female is "rounder" in body and has a larger abdomen where she carries eggs
  • Male develops black finnage. This differs from species, as for example, the male Honey gourami develops black all around its anal fin and lower body, but develops bright colours (like yellow, red and blue) on its dorsal. The anal and dorsal fins of 3-Spot male gourami both go very dark/black.

Some gouramis display more Sexual Dimorphism than others. In Honey Gourami, the males are a bright yellow/red, and the females are a dull grey (also with a line going through the middle of their body). In Thicklip "red" Gouramis, the female is the same colour as the male until he matures, in which he becomes a bright red and she stays the bright orange. In Pearl and 3-Spot Gourami, the female and male are both the same colour as each other.


Male and Female Thicklip Gourami

Above: A male Thicklip gourami at the front, female at the back.

Below: A female Indian Banded gourami has a very round abdomen.

Female Indian Banded Gourami / Fasciata


This sexing technique, however, does not apply to Betta spp. as they are sexed very differently. Betta males typically have longer fins, but in short finned varieties sexing may be more difficult. Females often have large abdomens and can also have what is called an "egg spot" (just before her anal fin, there is a little white spot) but some males may even carry egg spots! Females often have short dorsals and can have subtle differences in their fins, but it's not always a reliable sexing method. Typically in gourami, only males blow bubble nests. However, sometimes even female Bettas do this also!



There are two questions often asked about gourami. What fish can I keep them with, and can I mix species of gourami? Individuals of one species can often be very different and have a range of personalities, so often it comes down to the personality of your gourami. Most gourami are compatible with the same types of fish, but it's important to keep in mind that the males of all species can become very territorial and even aggressive when they're in breeding-mode! Because of this, I tend to keep gouramis in a Male:Female ratio of 1:2, as the can often pick on a single female and stress her out, so having 2 "shares" the stress between the two. It's also best to not keep large species such as 3-Spots and Pearl gourami with small, sensitive species such as quiet rasboras. The other fish need to be able to withstand the breeding behaviour of larger gourami, which can be very boisterous at times!

Keeping multiple males is a big No-no, as they will often fight and end up wounded and even ill. This, however, can sometimes be done when no females are present, and is often done with Dwarf gourami where here in NZ, females are rarely available. It's important to keep over 3 Dwarf gourami males if you are keeping multiple, as it spreads aggression and assures not one fish is being picked on all the time.

Many people forget to try to suit fish based on water hardness, pH and natural habitat. Fish such as Mollies (Poecilia sp) prefer hard, alkaline and even brackish environments and really aren't suitable tankmates for the gourami. It's a good idea to keep gourami with other Asian fishes, or even South American fish which often come from tanin-stained waters. Fish that prefer high flow aren't compatible with gourami unless you can set up different flow strengths at different ends of the tank.


Keeping Gourami with other Species

Here I will split these gourami above into separate groups of Aggressive, Mild, Sensitive and Miscellaneous.

Aggressive gourami need tank mates that can put up with territorial males, and will generally withstand the boisterousness of the species. Aggressive gourami are certainly mild in comparison to fish like Cichlids, but are certainly aggressive in comparison to the sensitive species. These gourami are typically pretty hardy, and don't mind other boisterous tank makes, but do need their territory.

Tank mates may include: Bottom dwellers (Corydoras, plecos, other catfishes and loaches), active Mid and Top dwellers (tetras and other shoaling species will keep gourami comfortable. Sometimes dwarf cichlids can work too).


Male Thicklip Gourami Wildtype

Above: The Thicklip Gourami can be considered a "Mild" tempered fish, but can become very territorial when breeding.


Mild gouramis are typically medium-sized gourami and are compatible with most fish. The males of this category are still very territorial, but are less likely to be aggressive with other fish and will simply chase them away. These guys are OK with fairly boisterous fish, and are better around more sensitive fish than the above category. These guys tend to not be so great with fish larger than them, however, and are still the bosses of the tank.

Tank mates may include: Anything around the same size as the gourami or smaller. Bottom dwellers can include anything, and can be slightly larger than the gourami as long as they are not predatory. Good with most mid-top dwelling fish.

Sensitive gourami prefer either species-only tanks or tanks with very quiet fish. Males are still territorial, but typically only to their species. These guys are easily picked on by anything bigger than them, and will be scared by very active fish. A nice, small, quiet tank is best for the sensitive gourami, where they have plenty of places to hide from other fish species and develop their own territories.

Tank mates may include: Bottom dwellers (Pygmy cories, whiptail catfish, otocinclus and other small, low-activity catfish. Most loaches are too active for this species, but Kuhlis may be an exception), quiet Top-Mid dwellers (rasboras, small tetras, some killifish and other quiet, small shoalers).


Male Red Honey Gourami Wounded

Above: Honey gourami are easily wounded by other fish, which can easily lead to death.


Miscellaneous gourami require different care to the above regarding tank mates. The Betta, specifically, needs tankmates which won't nip fins and are non-aggressive. The temperament of bettas ranges a lot, and some are too aggressive to live with other fish at all. Others are so shy any other fish stress them too much. Male Bettas should never be kept with females, and keeping multiple females (called a "sorority") has to be done with a lot of care.

Tank mates may include: Bottom dwellers (most catfishes are OK, but many loaches are too boisterous or nippy) and quiet Top-Mid dwellers (rasboras, some tetra species are less likely to nip fins than others. Tetras tend to nip fins less when kept in large shoals).


  • Three Spot Gourami, Trichopodus trichopterus
  • Pearl Gourami, Trichopodus leerii
  • Dwarf Gourami, Trichogaster lalius

Also includes the Giant gourami


  • Thicklipped Gourami, Trichogaster labiosa
  • Indian Banded Gourami, Trichogaster fasciata


  • Sparkling Gourami, Trichopsis pumila
  • Honey Gourami, Trichogaster chuna

Also includes the Licorice gourami and Chocolate gourami


  • Siamese Fighting Fish, Betta splendens

Also includes other Betta spp.



Keeping Different Gourami Species Together

This can be done, but requires extreme care. If you see one fish attacking others, it's important to remove the aggressor. Keep the wounded fish in a low-stress environment (whether it be its current tank or a hospital tank) and keep the water as clean as possible to ensure the wounds do not become infected.

It is possible to keep the Aggressive species listed, 3-Spot and Pearl gourami, together, the same goes for the Mild species.

The Sparkling gourami is simply too sensitive to keep with other gourami species. Because the Dwarf gourami is so prone to disease and the males are so territorial, it is ideal to keep this species on its own as stress and wounds can quickly become fatal.

Misc species such as Bettas should never kept with other anabantoids, as this can end up with very stressed fish or the Misc fish going on a killing spree!



In Conclusion

Gourami are extremely rewarding fish to keep, and are a perfect addition to any community tank. There are just so many different species to choose from, and even within species there are different varieties available!

Many gourami species are easy to keep provided they are kept with regular water changes to keep their environment clean and the appropriate temperature and tankmates. I recommend species such as the Thicklip gourami and Honey gourami to new fishkeepers, while experts can take on challenges for rarer gourami such as Chocolate, Sparkling or Licorice gourami. Gourami are even easy to breed! While not as simple as, for example, livebearers, gourami are good "newbie" fish for breeding and are excellent to introduction to things like pH, tanins and "different" ways of breeding such as bubblenesting.

I greatly enjoy taking care of my gourami, and hopefully this article has provided you with the information for doing so too! If you have any questions, feel free to contact us or ask your local fishkeeping forum!